Obesity is a serious health problem that has reached epidemic proportions in the U.S. today. Obese women have 60-120 percent greater risk of death than their leaner counterparts and even mild overweight heightens the risk of morbidity and mortality. Many overweight people attribute their weight management problems to an irresistible urge to consume high-carbohydrate (CHO) snacks when feeling dysphoric. These so-called "carbohydrate (CHO) "cravers" report mood elevation after eating foods rich in CHO. CHO craving garnered programmatic research attention in the 1980s, but methodological and conceptual difficulties led research on the phenomenon to dissipate. Currently, there is disagreement about whether the phenomenon of CHO craving even exists. Despite this, the CHO-craving concept continues to be widely used by obesity researchers and receives tremendous endorsement by the lay public. In reality, the CHO craving construct has yet to be systematically validated. Study 1 will determine whether the phenomenon of CHO preference can be objectively demonstrated and whether, as CHO-cravers claim, self-administering CHO dispels negative moods. Sixty mildly to moderately overweight females who report excessive consumption of high-CHO snacks will be tested in a substance self-administration paradigm. The aim is to see whether they systematically prefer CHO to protein when induced into a dysphoric mood, given a choice between novel taste and calorie-matched beverages, and blinded to information about their nutrient composition. This study will also test whether CHO intake improves the mood and cognitive performance of self-professed CHO cravers, and whether benefits are greater when CHO are chosen and self-administered, rather than experimenter-administered. Study 2 will compare CHO cravers and weight-matched controls on their insulin, tryptophan and leptin responses to the CHO beverage, as well as their familial history of Type II diabetes. Results will indicate whether CHO cravers show an increased family prevalence of diabetes and display evidence of insulin resistance and blunting of the expected rise in the tryptophan ratio and leptin concentration after CHO intake.